var number = 1
function withNum(number) {
  console.log('number', number)
}
withNum() // undefined
withNum(number) // 1
if (true) {
  var iF = 'blue'
}
console.log('iF', iF) // blue

var n = 1
function a () {
	console.log('n', n)
}
a()
//  n 1
function a (n) {
	console.log('n', n)
}
a()
//  n undefined
